Deku's Bizarre Adventure
by Zeldro
Summary: Dio finds a new world to take over after nearly destroying his: the My Hero Academia universe. He destroys UA high and wreaks havoc, unleashing monsters and death throughout the world. After meeting Jotaro, Joseph, and the others, it's up to Deku and the students of UA high to fight for their homeland, as well as their own lives. [Heavy Ochako/Izuku]
1. 0 - Prologue

_**Prologue**_

In the multiverse, there are currently four known universes: the _Legend of Zelda_ universe, the _Attack on Titan_ universe, the _Tokyo Ghoul_ universe, and the _One Piece_ universe. The former two and latter two have been connected due to special circumstances; certain beings have the power to create portals between the different universes.

This is a story of two more of those universes being connected.

In what we shall call the _Bizarre Adventure_ universe is a man named Joseph Joestar. During his fight with the evil Pillar Men, a power is unlocked that connects his universe with another: the _Hero Academia_ universe. However, he does not realize this until much, much later.

Decades later, he, along with his grandson, are searching for the evil Dio, and follow him to a portal that leads to a new universe - one filled with superpowers, heroes, and villains.

Their fate is bound with that universe, as well as Dio's. New threats will arise. New friends will be made. War will break out, and world-changing events will take place. And, somehow, a certain boy attending UA high will be right in the middle of it.

Follow Deku, Jotaro, Iida, Ochako, Joseph, Tsuyu, and many, many others, as they find themselves in a world ravaged by monsters, fighting for survival and the fate of both of their worlds.

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 **A/N: It is time for a brand new story for me to write alongside my other two fics, Straw Hat Ghoul and To Hyrule and Back Again. I have started planning, and am confident in the story and its future. This prologue may seem confusing and short, but is crucial for understanding future events. Chapter 1 should be out very soon.**


	2. 1 - New School

_**Deku's Bizarre Adventure**_

 _ **Act I**_

 **Chapter 1: New School**

Izuku "Deku" Midoriya is a boy, who, despite his piteous childhood, rose from the ashes of his defeat and managed to pull through and get accepted into his dream school, UA High. It was no simple feat - initially having no Quirk, he was always told to give up on his dream of becoming a hero, but after meeting All Might and inheriting One For All, he had the chance to pursue his dream. Pursue he did, as, after taking the entrance exam and passing, he realized he had finally done it. He had achieved one of his lifelong goals.

His view of the world is a cliche, clear-cut, stereotypical view; it is one that views all villains as evil and nothing more, and one that believes heroes will always save the day. That's how he thinks. Now, don't get me wrong, he is not naive, he simply doesn't think outside the box. For now, this is not a problem, but far in the future, his worldview will be put to the ultimate test.

He will make decisions where no choice is right or wrong. He will make sacrifices, and he will see people die. Unbeknownst to him, the future of his world solely depends on him, his actions, and his choices.

Let's not get too far ahead of ourselves, though. His adventure, which will be quite a bizarre one, is just beginning. It all starts with his first day at UA High.

 _This is it,_ Deku thinks to himself, trembling. _My first day of high school…_

The large school campus stands before the boy as he gazes upward. This isn't any run-of-the-mill academy, no, this is _the_ most famous high school for upcoming heroes. Deku, previously a Quirkless, is now attending said school.

 _After all those years of dreaming…_

"It's finally happening," he says to himself.

The sky above him is a vibrant blue. The bright sun shines down on him from behind, and a dense forest surrounds the area. A large gate stands in front of Deku, and behind that is the big, wondrous high school. He smiles, and steps forward.

The boy tries to not make eye contact with any other students. They were all surprised to hear the supposedly Quirkless boy had a hidden power used to knock down a giant foe during the entrance exam, and he doesn't know whether or not the others despise him. He wants to lay low for now.

But as he walks closer to the school, that wish of his is immediately gone.

"Izuku Midoriya?" a voice says from behind.

Deku hesitantly turns around to see a male student approaching him amongst all the others. He's wearing glasses, has dark hair, and looks very sophisticated. Deku's heart starts racing.

 _I-It's him! The one that's all serious about everything… He called me out for mumbling too loud during the presentation, now he probably thinks I cheated my way in. This can't be good…_

Iida Tenya holds out his hand and gives Deku a warm smile.

"Hello, I'm Iida, you saw me at the entrance exam, correct?" he asks, shaking Deku's hand.

"Uhh… Y-yes, yes I did!" he replies, filled with relief.

"Well, I certainly saw _you,_ and at first I was sure you wouldn't pass because of your supposed Quirklessness. But, you did, in fact, have a Quirk, but you simply never mentioned it."

"Oh, well, you know… I'm humble?"

"Indeed you are! I wanted to both congratulate you and thank you. You showed me more of what it means to be a hero - you took on a zero point foe to save Ochako, even if it meant sacrificing precious time, and thus, you were admitted because you showed true spirit. Good job."

 _This guy's reading wayy too far into things… I just got lucky. Lucky with pretty much everything._

"Thanks!" I enthusiastically respond. "I-um… I guess we'll see each other in class?"

"Yep, 1-A. Here's to a good first year at UA," Iida says, looking towards the school.

Meeting Iida put Deku's nerves at ease as he comes to the conclusion that the other students are more easygoing than he initially thought. Except for, of course, Kacchan. Still, he has made a new friend, as the two continue talking about the school whilst walking inside the giant facility.

"So, what is your Quirk called?" asks Iida.

Deku hesitates for a moment.

"It doesn't have a name, is it supposed to?" Deku replies, knowing not to say _One For All._

"Of course! Yours has no name? Was it recently manifested?"

Deku hesitates again; then, he responds, "No, it wasn't…"

"Then it should be given a proper name! Growing popularity early on can be helpful, and a catchy name is essential. With all of these sudden monster and villain appearances, hell, we might have to _actually_ fight, Izuku! We'd all be in the spotlight. So, I believe your Quirk is to be named right away."

"Monster appearances?" Deku confusingly asks. _What does he mean by that?_

"You haven't heard? All those newspaper articles about strange murders, zombie-like infections, and increased number of villains? It's become bad, especially around our area."

 _...What?_

Deku opens his mouth to ask Iida something but another voice calls out his name from behind. This time, it's a feminine voice.

"Deku!"

Izuku turns around. _Deku? Why that name? That's what Kacchan calls me, but that's supposed to be a way to tease me._

He sees a girl whom he instantly recognizes; she has long, brown hair, brown eyes, and a cheerful smile.

"D-deku?" he confusingly replies.

She approaches the boy. "That's your name, right?"

"Uh, well, no… You see, that's kinda a nickname that this one guy calls me… I prefer Izuku…"

"Oh. Well, I like the name 'Deku.'"

"You can call me Deku!" he suddenly says to her, blushing.

Iida looks to Deku in confusion. _He suddenly likes that name?_ he thinks.

"Okay! Cool! I'm Ochako Uraraka."

Iida takes a step forward, signaling to the others that it's time to keep moving. Deku and Ochako then start walking again, and the three begin chatting.

 _Don't be nervous… Don't be nervous… She's just a random girl._

 _A random girl that's really cute and nice, though…_

 _Don't screw it up, Izuku._

"Are you two ready for a semester of this amazing school?" she asks, starting a conversation.

Deku smiles. "Yes!" he says, along with Iida enthusiastically nodding.

"I heard All Might is teaching us, and that our homeroom teacher is Eraserhead," Ochako says.

"A-All Might?!" Deku blurts out. A few people turn their head to Deku.

"I know, right? I can't wait! I… I can already tell this year is going to be _fun._ "

Ochako gives Deku a blissful smile. He returns the favor, and, amongst the three freshmen at UA High, a bond begins to form. The first day of school for Deku starts out very smoothly; nothing bad or out of the ordinary happens.

The same cannot be said, however, for a certain group of men far away.

"OH MY GOD!" Joseph Joestar yells out. "Look at this view!"

Five men are standing on the edge of a cliff. An ocean stretches out before them, and a forest behind them. With Jotaro, Joseph, Kakyoin, Avdol, and Polnareff, these men are known as the _Stardust Crusaders._ They are from what is known as the _Bizarre Adventure_ universe.

"Is this where Dio now resides?" asks Avdol.

"I would imagine," replies Kakyoin. "Considering the state our world's in, it only makes sense he'd find another…"

The sun is rising in front of them, and the sky is gradually lighting up. The portal in which the men entered is now gone. Without a map or any knowledge of the _Hero Academia_ universe, the men set off into the forest behind them.

Unbeknownst to the group the portal had led them to the island of Japan. As they travel throughout the forest, Jotaro and the others slowly make their way towards a city - not Musutafu, where UA High is located, but one of its neighboring cities.

"Are we to assume this world has a different map?" Avdol asks.

Joseph looks to Avdol as the men duck under thick branches and past large trees.

"Not sure. We need to find a world map as soon as possible, in any case."

"How are we to track down Dio?" Avdol questions in response.

Purple vines suddenly come out of Joseph's arm. "Same old way."

Joseph looks down at the vines growing from his arm, thinking, _I wonder if this world has any Stand users…_

The men make their way through the woods. They wonder about the world they've just entered, and theorize how Dio was able to create a portal and travel here. Kakyoin notices a distinct "X" marked into a tree, and comments on it.

"What's this?" he asks.

"I don't know… It's too deep for a knife, but too small for an axe… Probably a bear or something. Let's keep moving," replies Avdol.

Some time later, a certain hero is sleeping on his bed. He's a teacher at UA High now, but had seemingly forgotten that today was the first day of school. With a scrawny build, shaggy blond hair, and dark eyes, he is one of the most popular heroes in Japan.

He is known as All Might.

Abruptly, his eyes open, and the hero immediately realizes that he's late. His small figure hops out of bed and gets ready as quickly as humanly possible, and after putting on his uniform he bursts out the door, transforming into his big, buff All Might form.

"Minor setback, but still ready," he says to himself.

The well-known hero hops from his doorway and easily glides into the city. Citizens immediately identify him and chant his name. He runs toward the high school, unbeknownst to the public, but gets sidetracked along the way with small problems. Purse snatchers, petty thieves, and gang members - he stops all of these villains every day, and today is no different. However, when he stops to get a cup of coffee, he notices a certain man across the street. He's yelling at the ATM for some reason.

"What is this black magic?" the old man says. "This is too complicated! ATMs aren't supposed to be this complicated!"

 _Looks like that old man is having trouble there… Maybe I should help him?_ he thinks.

 _I'm already late… Doesn't matter anyway._

As he stands in line to get his coffee, he then sees a shady man dressed in black with dark sunglasses approaching the old man across the street. The man pulls out a gun, and points it in the old man's face.

"Holy shit, a gun! I haven't seen one of those things in _forever_."

All Might starts to walk to the exit of the coffee shop as his fans cry for him to stay. He carefully watches the event go down in front of him with confusion.

"Oi, get me some of that money for me out that ATM, ya hear me?" the bandit tells the old man.

"Well, asshole, I can't even figure out how to work it, so _tough luck!_ "

The bandit starts to pull the trigger, but suddenly, purple vines grow out of the old man's body, and they wrap around the bandit's pistol. Then, the pistol is ripped from his hand, and Joseph Joestar grabs it and points it in the other man's face. Naturally, no one around him can see said vines.

 _That old man's Quirk… I've never seen anything like it,_ All Might thinks. _It's some form of telekinesis, but it's like he's controlling an invisible rope or something._

 _Looks like he can take care of himself, too…_

A group of men approach the old man and one of them begins speaking with him. He's got a hat, dark clothing, and a menacing look.

"Just shoot him already, we need to get going."

"I hate guns! I'm not doing shit."

"Fine, I'll take care of it," Jotaro replies.

The bandit starts running, but Star Platinum charges forward and bashes him to the ground. Jotaro walks forward as the surrounding citizens look on in total awe and confusion.

"Trying to rob my grandpa, huh? Can't get money on your own? Too much of an idiot to do things yourself?"

The bandit shrivels on the ground on looks up to Jotaro in fear. He raises up his hands in submission for a moment; Jotaro rolls his eyes and sighs.

"Go. Get out of here," he says.

But the bandit doesn't move; instead he smirks and takes off his sunglasses. His eyes are all red, with no pupils. Abruptly, two lasers shoot out of his eyes, go through Star Platinum, and hitting Jotaro. He writhes in pain for a moment before Avdol summons his Stand.

Magician's Red slaps the bandit with its fiery fist, and when Polnareff summons Silver Chariot his Stand slices the bandit's chest. The bandit falls to the ground again, injured, and tries to crawl away from the Crusaders.

"Futile effort," Kakyoin remarks. "Didn't even require my assistance."

All Might, in total shock, stares at the _Stardust Crusaders_ from across the street, now outside the coffee shop. He, not being a Stand user, just saw a man get beaten by invisible beings somehow connected to the men he sees. Wary yet curious he heads on over toward the men and attempts to strike up a conversation.

"You guys… How were you able to do that? Was it your Quirks?"

Jotaro looks behind for a moment. He sees All Might, then turns back around.

"How annoying," he says under his breath.

"Where are you people going?" All Might questions. "You are all heroes! I've never seen you before, but I want to talk!"

"Your Quirks are amazing!" he continues. "It's like they're invisible monsters! Don't be like that, let's get to know each other!"

"Non-Stand users need not know anything about our travels," Kakyoin tells him whilst walking.

 _Stand users? Is that their type of Quirk or something?_ All Might thinks.

All Might jumps over the men and lands in front of them. He shoots them all a big smile and begins talking again.

"Come on, guys, be cool. Why not go grab some coffee?"

"Get the _fuck_ out of our way before I rip those teeth out," Jotaro threatens.

All Might isn't sure whether or not Jotaro is being serious, and that scares him a bit. He doesn't move, though; he knows this new "Quirk" would be in the papers big time, as he's never seen any people with very similar quirks that are this unique. He won't take no for an answer, either.

Jotaro passes by the buff hero and the hero turns and puts his hand on Jotaro's shoulder, still trying to convince him. Star Platinum promptly punches All Might in the face - so hard that he reverts to his original, scrawny form, and he's sent back a few meters.

He lays there on the concrete, looking to the men, getting a bit frustrated; he changes back to his hero form before anybody notices, and starts making his way to UA High. Whilst doing so, he can't get Jotaro, Joseph, or the other men out of his head.

 _It's like they didn't know who I was, or at least didn't care… Are they heroes, or villains? Something in between?_

 _Either way, I need to make sure they don't cause any problems… I'll deal with that later._

But when All Might finally reaches UA High an entire city over, he realizes today really _was_ the worst possible day to be late.

 **. . .**

 _ **a few hours earlier**_

Izuku Midoriya, otherwise known as Deku, is sitting in class, waiting for his homeroom teacher. He's on the back row, with Iida Tenya in front of him, Ochako Uraraka to the right of him, and Asui Tsuyu to the left.

 _Where is the teacher?_ Deku thinks. _Class should've started fifteen minutes ago…_

Deku, with nothing else to do, pulls out his phone. A notification pops up: "BREAKING NEWS - MONSTER INFESTATION SPREADS TO MUSUTAFU"

 _That's the city we're in… Oh my God!_

He opens the news app and sees the front page. A few articles concerning "monster attacks" in his city are there, and once he checks other sites he sees the same thing. Deku starts sweating, his heart starts pumping, and he realizes what Iida was saying earlier is real.

Deku's too nervous to say anything, but also too scared to not take action. He decides to get up and say he's going to the bathroom. _Maybe it's just a couple of random infected citizens some villains made… All Might is probably on it right now._ Deku walks down the silent hall of UA High.. He turns into the boy's bathroom and looks in the mirror; he sees his nearly-distraught face.

 _No… Iida said something about recent monster attacks… I hadn't heard anything about it before then. But… If it's breaking news, then it's serious… Villains attack all the time. They're usually stopped by heroes, and it's not that newsworthy._

 _This, however… is on the front page of every major news outlet in Japan._

He sighs. _It's not like they could get in_ _ **here,**_ _right? This school has top-notch security. Plus, tons of heroes work here, so we'd be safe even if any did get in._

Deku stares at himself in the mirror, with a concerned look.

 _Nevertheless… It's never bad to be cautious…_

A mere second after that thought, a green-ish figure appears from behind Deku in the mirror. They make eye contact. Deku freezes. He realizes a zombie is behind him. The zombie starts reaching for Deku, and he continues standing still. _Is this real?_ he thinks.

Kacchan appears out of nowhere and blows the zombie's head off with ease. He then looks to Deku.

"Deku… you fucking _idiot!_ You knew about this, and you didn't say a _goddamn_ thing! Useless…"

Kacchan strikes another zombie heading his way with his explosive Quirk as Deku stands there in confusion.

"Don't get in my way!" he yells.

Sirens suddenly start sounding. Loud voices and screeches are heard, along with zombie groaning and distinct hissing. UA High is under attack, all while All Might and Eraserhead are absent. This attack is being caused by none other than Dio, who, after figuring out how the hero system of the _Hero Academia_ world works, decided to strike the best training school in Japan.

Today, on his first day of school, is when this boy's life starts to change. It is the first moment that makes him realize that anything can happen at any time, good or bad. Thus, Deku's Bizarre Adventure finally begins.

 _ **TO BE CONTINUED**_

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 **A/N: Thank you for reading the first chapter. This is my third crossover story, and is apart of something much, much bigger. Make sure to review if you want to comment on anything or give me criticism, both of which is much appreciated.**

 **I'm also on the lookout for a betareader for this story as of 5/26/17. I need someone to check for grammar mistakes, improve wording and/or flow of the future chapters. PM me if you're interested.**

 **twitter: byzeldro**

 **tumblr: zeldro**

 **I post updates about my stories, as well as previews, on both my Twitter & Tumblr.**

 **One more thing: On future chapters of all of my stories, I will start putting other fanfictions that I like at the bottom of each new chapter , and also state to go check them out. It'll usually be one per chapter, but there may be exceptions. I already have some fics in mind, but if you want me to put yours, PM me.**


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